Insurance Australia Group Ltd (ASX: IAG) shares have far outpaced the returns from Suncorp Group Ltd (ASX: SUN) shares over the past year.

In afternoon trade today, Suncorp shares are down 0.5% at $20.76 apiece. That leaves the Suncorp share price up 9.7% over 12 months. Suncorp shares also trade on a 4.1% fully franked trailing dividend yield.

Meanwhile, IAG shares are down 0.3% today, changing hands for $8.68 apiece. This sees shares in the insurer up an impressive 35.5% since this time last year. At current levels, IAG trades on a partly franked trailing dividend yield of 3.3%.

That's the year gone by.

With an eye on the year to come, which S&P/ASX 200 Index (ASX: XJO) insurance company does Macquarie Group Ltd (ASX: MQG) forecast to have more upside?

Let's find out.

Will Suncorp or IAG shares outperform?

In a research report released earlier this week, the analysts at Macquarie noted:

The Australian General Insurance industry continues to focus on claims inflation. Our data suggests that claims inflation for Home reached its peak in the Dec '22 quarter, while Personal Motor peaked in the Mar '23 quarter. Nevertheless, "mix" has become a structural challenge.

The analysts added, "We estimate that IAG and SUN are continuing to reprice ahead of claims inflation, with underlying margins expected to peak in FY25."

Macquarie maintained its neutral rating for both Suncorp and IAG shares. However, the broker said it had shifted its preference to Suncorp.

Macquarie has a $19.20 12-month price target on Suncorp shares, or 7.5% below current levels.

The broker's 12-month price target for IAG shares is $8.70, or around 0.2% above current levels.

What's the latest from the ASX 200 insurance stocks?

Suncorp reported its half-year results on 12 February.

The Suncorp share price closed up 1.3% on the day after reporting an 8.9% increase in general insurance gross written premium (GWP) to $7.5 billion.

Investors were also clearly pleased by the 30% boost in cash earnings to $860 million. And Suncorp's net profit after tax soared 89% to $1.1 billion. Though I should note that includes the proceeds from the sale of its banking business to ANZ Group Holdings Ltd (ASX: ANZ) last July.

IAG reported its own half-year results on 13 February. Despite some strong growth metrics, IAG shares closed down 12.6% on the day.

Highlights included a 6% increase in GWP to $8.43 billion.

And net profit after tax (NPAT) surged 91% to $778 million.

As the Motley Fool reported on the day, the big profit boost, which failed to lift IAG shares on the day, was driven by a $140 million post-tax release of the COVID Business Interruption provision, an increase in net earned premiums, and an improvement in IAG's insurance profits.